Burner systems for domestic convection ovens have provided large combustion and/or mixing plenums due to the large burner flame lengths. Also large amounts of excess air, are used at normal baking temperatures since, when the oven is run at its maximum temperatures such as for self-cleaning, the mass of air circulated is reduced. It has been usual to vent the oven directly and to use relatively high pressure blower systems to maintain sufficient flow of excess air through the burner system at self cleaning temperatures so that undesirable generation of noxious fumes such as carbon monoxide does not occur.
In addition, it has been difficult to adequately monitor actual flow of air into the burner system so that if the blower fails the burner will reliably shut down.